Electrical gas discharge tube counting or distributing circuits



13, 1959 J. H. BEESLEY ,9

ELECTRICAL GAS DISCHARGE TUBE COUNTING OR DISTRIBUTING CIRCUITS Filed May 3, 1956 3 Sheets-Sheet l 2 I u 3) Signal Input- CircuiI" I Conrrol Device 2 L I 1 28, 5L

Inn/5 Tola' ITTORNEY I Aug. 18, 1959 H, BEESLEY 2,900,571 A ELECTRICAL GAS DISCHARGE TUBE COUNTING OR DISTRIBUTING CIRCUITS Filed May 3, I956 5 Shets-Sheet 2 I Con l'rol A Device IN VEN TQR 044M /ENRy 856545 Aug-v 1959 J. H. BEESLEY ,90

ELECTRICAL GAS DISCHARGE TUBE COUNTING OR DISTRIBUTING CIRCUITS Filed May 3, 1956 v 3 Sheets-Sheet 3 26 1 -""--i.' "1 a 2 c i MH 24 38 I24 2 l l 54 i i 25 25 I Mvsumq JOHN ENRY FEFSLEY DTToRNcY United Sttes Yatent O ELECTRICAL GAS DISCHARGE TUBE COUNTING OR DISTRIBUTING CIRCUITS John Henry Beesley, Learnington Spa, England, assignor to The General Electric Company Limited, London, England This invention relates to electric counting or distributing circuits that employ gas discharge tubes of the kind having an anode, a cathode and a trigger electrode, the anode and cathode forming a main discharge gap and'the trigger electrode forming an auxiliary discharge gap with the cathode. Gas discharge tubes of the kind specified above are hereinafter referred to as gas tubes.

The invention is particularly, but not exclusively, concerned with electric counting or distributing circuits that employ cold cathode gas discharge triodes.

It is an object of the present invention to provide improved electric gas tube circuits of the kind operable to count or to distribute electric signals occurring on two or more input leads.

According to the present invention, an electric counting or distributing circuit includes a small plurality of input leads, a small plurality of control devices connected to the input leads, a small plurality of signal carrying leads which are each connected to a difierent one of the control devices and a plurality of gas tubes connected in cascade to form a chain, adjacent gas tubes along the chain being associated with different ones of the signal carrying leads and with diiferent ones of the control devices and the control devices being arranged to act in response to electric signals to be counted or distributed occurring on the input leads to apply voltage signals of a predetermined value to the signal carrying leads, the arrangement being such'that each gas tube in the chain is, during operation, rendered conducting, upon the occurrence on the associated signal carrying lead of a voltage signal of the predetermined value only if the preceding gas tube in the chain is then conducting, and the conduc tion of the first gas tube of any pair of the said gas tubes that occupy adjacent positions in the chain results in the extinction of the anode to cathode discharge in any pre viously conducting gas tube and determines that the next voltage signal shall occur on the particular one of the signal carrying leads which is associated with the second gas tube of the said pair,

According to a feature of the present invention, each control device has an input circuit and an output circuit, the input circuits being connected to the gas tubes and to one of the input leads and the output circuits being each connected to a difierent one :of the signal carrying leads, each gas tube being connected to only one of the input circuits and the arrangement being such that, during operation, a control device responds to electric signals occurring on the input leads to which it is connected only if one of the gas tubes connected to the input circuit of that control device is conducting, each control device acting when so responded to apply-a voltage signal of the predetermined value to the signal carrying lead which is connected to its output circuit and the signal carrying lead to which such a voltage signal is applied being associated with the gas tube which succeeds the conducting gas tube in the chain.

Each control device may include a second plurality of gas tubes which are equal in number to the said input ice leads and which are connected in cascade to form an open chain, the input circuit of each control device being connected to a first one of the input leads and to the first gas tube of the subsidiary chain formed by the associated second plurality of gas tubes and the output circuit of each control device being connected to the last gas tube of the associated subsidiary chain, the arrangementbeing such that when the first gas tube of a subsidiary chain is rendered conducting in response to an electric signal on the first input lead, all the remaining gas tubes of that chain are able to be rendered conducting in turn each in response to an electric signal on a difiiereut one of the remaining input leads, the last gas tube of a subsidiary chain acting when rendered conducting to cause a voltage signal on the signal carrying lead and the first gas tube of a subsidiary chain being rendered conducting as aforesaid only when one of the associated gas tubes of the first said plurality of gas tubes is conducting.

It may be arranged that each gas tube in the said subsidiary chains acts when rendered conducting to cause the extinction of the anode to cathode discharge in any previously conducting gas tube in the said subsidiary chains,

Preferably, a counting or distributing circuit according to the present invention includes two input leads and two signal carrying leads, alternate gas tubes along the main chain formed by the first said plurality of gas tubes being associated with the same one of the signal carrying leads and it being arranged that during operation a voltage signal of the predetermined value is applied to one of the signal carrying leads in response to electric signals occurring one on each input lead in a predetermined sequence.

A counting or distributing circuit according to the pres ent invention will now be described, by way of example, with reference to the six figures of the accompanying diagrammatic drawings in which:

Figures 1 and 2 should be laid side by side with the right hand edge of Figure 1 against the left hand edge of Figure 2 to show the complete circuit.

Figure 3 shows the electric circuit of one form of the signal input circuit shown in block form in Figure 1,

Figure 4 shows the electric circuit of a second form of the signal input circuit shown in block form in Figure 1.

Figure 5 shows the electric circuit of one form of the control device which is shown in block form in'Figures 1 and 2 and which is suitable for use with the signal input circuit of Figure 3, and

Figure 6 shows the. electric circuit of a second form of the control device which is shown in block form in Figures 1 and 2 and which is suitable for use with the signal input circuit of Figure 4.

The electric circuit shown in Figures 1 and 2 has two input terminals 1 and 2 and is operable to count or to distribute electric signals applied to the input terminals 1 and 2. The counting or distributing is carried out by a plurality, say eleven, of cold cathode gas discharge triodes which are connected in cascade to form an open chain and of which only the gas triodes 11 to 15 providing the last five stages 'of'the chain are shown. I

Each of the gas triodes 11 to 15 and the like has its anode connected to a lead 3 and'thence by wayof-a common resistor. 4 to a terminal 5. During operation of the circuit an electric power supply is connected be tween the terminals'S and earth so that the lead 3 is at a positive potential to earth. This potential is of a value between the anode to cathode discharge maintaining and discharge initiating value for any one of the gas triodes 11 to 1'5 and the like. It is thus arranged that a gas triode of the chain is only :able to be rendered conducting by transfer of a trigger electrode to cathode discharge to its anode to cathode gap. As will be described more work having two parallel arms. One of these arms com-' prises a resistor 6 and the other arm comprises a resistor 7 in Series with a capacitor 8. When any one of the gas triodes 11 to and the like is rendered conducting, the resulting anode to cathode discharge current flows through the associated resistor 6 and the cathode of the conducting gas triode attains, after a short interval in time, a steady voltage which is positive to earth. The value of the resistor 6 is so chosen that this steady voltage is sufficient to initiate a trigger electrode to cathode discharge inany other one of the gas triodes when, as will be apparent hereinafter, it is applied between those electrodes. The cathode voltage of a conducting gas triode rises exponentially to a steady value due to the associated capacitor 8. 'Similarly, when the anode to cathode discharge in any conducting gas triode is extinguished, the cathode voltage of that gas triode falls exponentially from the steady value to earth potential. This exponential rise and fall in'cathode voltage is employed in conjunction with the voltage drop across the resistor 4 to extinguish the anode to cathode discharge in any previously conducting gas triode when a further gas triode is rendered conducting;

The value of the resistor 4 is so chosen that when any twoof the gas triodes 11 to 15 and the like are conducting simultaneously across their anode to cathode gaps, the resulting voltage of the lead 3 relative to earth is insuflicient to maintain an anode to cathode dischargein any gas triode having its cathode positive to earth by an amount substantially equal to the said steady voltage. If the said two gas triodes are rendered conducting sequentially so that the cathode of the first is at the said steady voltage before the second is rendered conducting then the capacitor 8 in the cathode circuit of the said first gas triode will prevent the cathode voltage of that gas triode from falling much below the said steady voltage until the extinguishing process is completed. The corresponding capacitor 8 in the cathode circuit of the said second gas triode will prevent the cathode of that gas triode from rising more than a few volts positive to earth during the time taken to' extinguish the said first gas triode. It will be appreciated that under the aforesaid conditions only the first said gas triode will be extinguished; i

In the chain formed by the gas triodes 11 to 15 and the like, each gas triode other than the gas triode 15 has its cathode connected to the trigger electrode of the succeeding gas triode in the chain by way of a signal gatingcircuit. Two signal'carrying leads 9 and 10 are provided which are connected to earth by way of resistors 19 and respectively and to which the said gating circuits are connected. Alternate'gating circuits along the chain are connectedto the same signal carrying lead 9 or 10. The electric circuit of each said gating circuit is identical so that only one will be considered in detail as follows:

The voltage which occurs at the junction of the resistor 16 and the rectifier element 18 and which is applied over the rectifier element 17 to the trigger electrode of the gas triode 12 is thus arranged to be substantially less than the said steady voltage. It now a positive voltage signal of value at least equal to the said steady voltage is applied to the-lead 10, the rectifier element- 18 ceases; to conduct. The voltage at the trigger electrode of the gas l triode 12 thus rises to the value of the said steady voltage and a trigger electrode to cathode discharge is initiated in the gas triode 12. The gas triode 12 is rendered conducting by transfer of the said discharge to its anode -to cathode gap and as a result, the anode to cathode discharge in the gas triode 11 is extinguished in the manner described above. Upon the conduction of the gas triode 12 the positive voltage on the lead 10 may be discontinned since it serves no part in the continued operation of the gas triode 12. a

From the foregoing description it will be appreciated; that the gas triodes 11 to 15 and the like can be rendered conducting in sequence along the chain each as the result of a positive voltage signal of the aforesaid value applied to one'or other of the signal carrying leads 9 and 10. Each of the gas triodes 11 to 15 and the like has an output terminal 21 connected to its cathode so that the said steady voltage which occurs at the cathode of a conducting gas triode is available as an output signal.

Two conditions must be fulfilled if every one of the positive voltage signals applied to the leads 9 and 10 is associated with the gas triode succeeding the then conducting gas triode.

That the first of these conditions shall apply is readily apparent from the previous description taken in conjunction with Figures 1 and 2 of the drawings. In connection with the second of the said conditions, let it be assumed that the gas triode 11 is conducting previously to the application of a sequence of the said positive voltage signals to be counted or distributed to the signal carrying leads 9 and 10. The succeeding gas triode 12 of the chain is associated with the lead 10 and is only able to be rendered conducting in response to a positive voltage signal on this lead 10. If then the first said positive voltage signal of the sequence to be counted or distributed is applied to the signal carrying lead 9 it is inefiective so that the said sequence of signals are not counted or distributed cor-' I provided. These control devices 22 and 23 are con- -The cathode of the gas triode 11 is connected to the trigger electrode of the gas triode 12 by way of a resistor 16 and a rectifier element 17 in series. The junction of these two elements 16 and 17 is connected to the signal carrying lead 10 by way of a further rectifier element 18. Each of the rectifier elements 17 and 18 is connected so as to be conductive to conventional current flow from the cathode of the gas triode 11. As stated above, the lead 10 is connected to earth over a resistor 20. If then the gas triode 11 is rendered conducting, the resulting steady voltage at its cathode is applied across the potentiometer formed by the resistor 16, the rectifier element 18 and the resistor 20 m series,

nected to two input leads 24 and 25 and thence by way of a signal input circuit 26 to the terminals 1 and 2. As will be described more fully hereinafter, each control device 22 and 23 has an input circuit and an output cir ouit. The output circuit of the control device 22 is connected to the signal carrying lead 9 and the output circuit of the control device 23 is connected to the signal carrying lead 10. Each of the said input circuits is connected to the input lead 24 and to one or other of two control leads 27 and 28. The odd gas triodes 11, 13, 15 and the like have their cathodes connected, each by way of an individual rectifier element 29, to the control lead 28 and thence to thecontrol device 23 which is associated, by way of the signal carrying lead 10, with the even gas triodes 12, 14 and the'like. Similarly, the even gas triodes 12, 14 and the like have their cathodes connected,

each by way of an individual rectifier element 30, to the control lead 27 and thence to the control device 22 which is associated, by way of the signal carrying lead 9, with the odd gas triodes 11, 13, 15 and the like.

In the above manner it is arranged that when, for example, the gas triode 11 is conducting, the steady voltage developed at the cathode of that gas triode 11 is applied over the associated rectifier element 29 to the control lead 28. The input circuit ofeach control device 22 and 23 is such that unless the said steady voltage is applied to its associated control lead 27 or 28 it will not respond to the electric condition which occurs on the input lead 24 when an electric signal to be counted or distributed is applied to the input terminals 1 and 2. Only the input circuit of the control device 23 responds when the said electric condition occurs on the input lead 24. In so responding the said input circuit enables the control device 23 to operate to a further electric condition which subsequently occurs on the input lead 25. When the cont'rol device operates it causes a voltage signal, which is positive to earth by an amount substantially equal to the said steady voltage, to be applied to the signal carrying lead 10. As a result of this positive voltage signal the gas triode 12 is rendered conducting and in so doing causes the anode to cathode dischange in the gas triode 11 to be extinguished in the manner previously described, thereby restoring the control lead 28 to earth potential.

The steady voltage at the cathode of the gas triode 12 is applied over the associated rectifier element 30 to the input circuit of the control device '22. This input circuit responds to an electric condition occurring as aforesaid on the input lead 24 and the control device 22 thereafter operates to the electric condition occurring on the input lead 25. The resulting positive voltage signal on the lead 9 causes the gas triode 13 to be rendered conducting so that the gas triode 12 is extinguished and the control lead 27 restored to earth potential. 7

It will be appreciated from the above that when, during a counting or distributing operation, one of the gas triodes 11 to 15 and the like is conducting, that gas triode automatically determines that the next positive voltage signal shall be applied to the signal carrying lead 9 or which is associated with the succeeding gas triode in the chain.

The electric circuit of the signal input circuit 26 may take on any one of a number of forms of which two are shown in Figures 3 and 4. The signal input circuit shown in Figure 3 is suitable for those applications where each electric signal to be counted or distributed comprises two voltage pulses which are positive with respect to earth and which are applied sequentially each between a difierent one of the input terminals 1 and 2respectively and earth. In the particular application considered above it would be necessary to arrange that the first voltage pulse of an electric signal is applied between the input terminal 1 and earth, whereafter the other voltage pulse of the electric signal is applied between the input terminal 2 and earth. The purpose of the resistors 33 and 34 which are connected between the input leads 24 and 25 respectively and earth is to main tain the input leads 24 and 25 at earth potential in the absence of voltage pulses on the input terminals 1 and -2 respectively. 1

"operated by the relay A'when its winding 35 is energised.

contacts A1 comprise a spring contact 36 which .is "connected to earth, a fi xed contact 37 which is connected to the input lead 24 and a moveable contact 39 which is connected to the input lead 25. As shown in the drawings, the spring contact 36 is normally in engagement with the fixed contact 37 so that the input lead 24 is at earth potential. When the contacts A1 are operated, the moveable contact 38 engages with the spring contact 36 and thus moves this contact 36 out of engagement with the fixed contact 37. During the operation of the contacts A1 there is a short interval in time'when both input leads 24 and 25 are connected to earth whereafter the earth is disconnected from the input lead 24.

When the signal input circuit 26 is of the form shown in Figure 3 the electric circuit of each of the control do vices is preferably of the form shown in Figure 5. Similarly, when the signal input circuit 26 is of the form shown in Figure 4 the electric circuit of each of the control devices 22 and 23 is preferably of the form shown in Fig-' ure 6.

The control device 22 which is shown in Figure 5 comprises an input circuit, an output circuit and two cold cathode gas discharge triodes 41 and 42 which are connected in cascade to form an open chain. The cathode circuits of the gas triodes 41 and 42 are identical in all respects with the cathode circuits of the gas triodes 11 to 15 and the like (Figures 1 and 2) so that the same reference numerals are employed. The anodes of the gas triodes 41 and 42 and of the corresponding gas triodes (not shown) in the control device 23 are connected together over a lead 43 and thence by way of a common resistor 44 to a terminal 45. The terminal 45 and the resistor 44 are shown in Figures 1 and 2 and correspond in function to the terminal 5 and the common resistor 4 of those figures. Thus during operation of the counting or distributing circuit (Figures 1 and 2) an electric power supply is connected between the terminal 45 and earth. The voltage value of this power supply in relation to the anode to cathode discharge maintaining and discharge initiating voltages for the gas triodes 41, 42 and the like is as hereinbefore described in connection with the power supply to the terminal 5 and the gas triodes 11 to 15 and the like. Thus the conduction of any one of the gas triodes 41, 42 and the like results in the extinction of the anode to cathode discharge in any previously conducting gas triode 41, 42 and the like in either one of the control devices 22 and 23.

The input circuit of the control device shown in Figure 5 includes a resistor 39 and a rectifier element 40 connected in series and in that order between the input lead 24 and the control lead 27. The junction of these two elements 39 and 40 is connected over a rectifier element 47 to the trigger electrode of the gas triode 41. The rectifier elements 40 and 47 are each connectedso as to be conductive to conventional current flow from the said junction to the control lead 27 and to the said trigger electrode respectively.

The cathode of the gas triode 41 is connected to the trigger electrode of the gas triode 42 by way of a signal gating circuit of the kind hereinbefore described in connection with the gas triodes 11 and 12 (Figure 1). It is thus arranged that the steady voltage which occurs at the cathode of the gas triode 41, when conducting, is only applied in full to the trigger electrode of the gas triode 42 when a voltage pulse of at least the same value and polarity as the said steady voltage is applied between the input lead 25 and earth.

The output circuit of the control device 22 includes the resistor 6 in the cathode circuit of the gas triodes 42 and a rectifier element 46 which is connected between the cathode of the gas triode 42 and the signal carrying lead 9 so as to be conductive to conventional current flow from the said cathode to the lead 9. The steady voltage which occurs at the cathode of the gas triode 42 when conducting is thus applied over the rectifier element 46 to the lead '9.

The voltage pulses which, during a counting or distributing operation, are applied between the terminals 1 and 2 and earth and thence by way of the signal input circuit 26 of Figure 3 to the input leads 24 and 25 are arranged to be of a value which is at least equal to the steady voltage occurring at the cathode of the gas triodes 41, 42 or the like when conducting. As previously described, a voltage of the same value as the said steady voltage is applied to the control lead 27 when any one of the even gas triodes 12, 14 or the like of the circuit shown in Figures 1 and 2 is conducting. If during a counting or distributing operation none of the even gas triodes 12, 14 and the like is conducting then the control lead 27 is at earth potential. it then a voltage pulse is applied between the input lead 24 and earth the rectifier element 40 conducts so that the voltage applied to the trigger electrode of the gas triode 41 is insuflicient to render that gas triode 41 con- .ducting. A positive voltage of the aforesaid value on the control lead 27 prevents the rectifier element 40 from conducting when a voltage pulse is applied to the input lead 24. This voltage pulse is therefore applied in full across the trigger electrode to cathode gap of the gas triode 41 and initiates a discharge between those electrodes. This discharge transfers to the anode to cathode gap of the gas triode 41 by virtue of the voltage of the lead 43. The resulting steady voltage at the cathode of the gas triode 41 is gated to the trigger electrode of the gas triode 42 when a voltage pulse is applied between the input terminal 2 and earth. The gas triode 42 then conducts and in so doing causes the anode to cathode discharge in the gas triode 41 to be extinguished. The resulting steady voltage at the cathode of the gas triode 42 is applied over the rectifier element 46 to the signal carrying lead 9 and renders conducting that one of the odd gas triodes 11, 13, and the like (Figures 1 and 2) which succeeds the particular one of the even gas triodes 12, 14 and the like which is then conducting. The electric circuit of the control device shown in Fig- Dre 6 diifers from the circuit shown in Figure 5 only in the form of its input circuit. Corresponding elements in the two circuits (Figures 5 and 6) are therefore referenced with the same reference numerals.

The input circuit of the control device 22 shown in Figure 6 includes a resistor 48 and a rectifier element 49 connected in series and in that order between the control lead 27 and the input lead 24. The junction of these two elements 48 and 49 is connected over the rectifier element 47 to the trigger electrode of the gas triode 41 and the rectifier element 49 is connected so as to be conductive to conventional current flow from the said junction to the input lead 24. The input lead 24 is normally connected to earth over the contacts A1 (Figure 4) so that the rectifier element 49 will conduct in the event of a positive voltage being applied to the control lead 27. If therefore one of the even gas triodes 12, 14 or the like (Figures 1 and 2) is conducting the resulting positive voltage on the control lead 27 is prevented from initiating the operation of the gas triode 41. Upon the operation of the relay A (Figure 4) in response to an electric signal to be counted or distributed, the earth is disconnected from the input lead 24 and connected to the input lead 25. The disconnection of the earth from the input lead 24 renders the rectifier element 49 ineffective so that the gas triode 41 is rendered conducting. The resulting steady voltage at the cathode of the'gas triode 41 is prevented from rendering the gas triode 42 conducting since the rectifier element 50 is conducting. Upon the termination of the electric signal supplied to the terminals 1 and 2 the relay A (Figure 4) releases and its contacts A1 restore. The resulting disconnection of the earth from the input lead 25 renders the rectifier element 50 ineffective and the gas triode 42 consequently conducts with the results previously described. 7 Each of the gas triodes 11 and 15 and the like of Figures l and 2 and the gas triodes 41, 42 and the like of the control devices (Figures 5 and 6) has a rectifier element in its trigger electrode circuit. 'Such an element is the rectifier element 4'1 which is connected in the trigger electrodecircuit of the gas triode 41 of Figures 5 and 6. The function of the rectifier elements 47 and the like is to prevent conventional current flow from the associated trigger electrode as may otherwise occur when the gas triode is rendered conducting. Such current flow is found to be undesirable in practice since it may result in damage to the-gas triode. The said certifier elements 47 and the likealso provide a low resistance to conventional current flow towards the associated trigger electrodes. This is desirablesince the lower the resistance of the trigger electrode cricuit of a gas triode the shorter the time taken be tween the application of a suitable voltage between the circuit of the trigger electrode and the cathode of the gas triode and the initiation of a discharge between those electrodes. p

The rectifier elements 47 and the like tend to isolate their associated trigger electrodes. To overcome this, each of the gas triodes 11 and 15 and the like and 41, 42 and the like has its trigger electrode connected to its cathode by way of a resistor 51. The value of the resistors 51 is very large, being in the order of several megohms. t

If the number of gas triodes 11 to 15 and the like in the main chain is a multiple of the number of signal carrying leads 9 and 10 then the said gas triodes of the main chain may be connected in a closed chain it so desired. That is to say, the gas triode 15 may have its cathode connected to the trigger electrode of the first gas triode in the chain by way of a signal gating circuit in the same way as the gas triode 11 say is connected to the gas triode 12.

The number of gas triodes in each control device 22 or .23 will usually correspond to the number of input leads ,24 and 25, each gas triode of a control device 22 or 23 being rendered conducting by electric signals occurring on a diiferent one of the input leads 24 and 25 in such a .manner that the sequence in which the gas triodes can be rendered conducting corresponds to the sequence in which, during operation, the electric signals occur in the input leads.

I claim:

1. An electrical counting circuit comprising a plurality of gas tubes connected in a chain and each having an anode, a cathode and a trigger electrode, the gas tubes forming a lesser plurality of groups than there are gas tubes and each group comprising at least two of the gas tubes that occur in the chain at a regular spacing which is the same for each group and which is such that adjacent gas tubes in the chain belong to different groups, individual resistance means connected in series with the anode to cathode gap of each gas tube to provide an electric signal when the associated gas tube is conducting, a separate signal carrying lead for each group of gas tubes, a separate coincidence device between each pair of consecutive gas tubes in the chain, each coincidence device having an input circuit connected across the resistance means of the first gas tube of the associated pair, an output connected to the trigger electrode of the second gas tube of that pair and an input connected to the particular signal carrying lead associated with the said second gas tube and operating upon a coincidence of electric signals applied to its input circuit and its input from said resistance means and said particular signal carrying lead to apply an electric signal to its output and thereby to strike said second gas tube, mutual extinguishing means which includes individual capacitance connected to each gas tube and resistance connected in common to all the gas tubes and which is to extinguish a conducting gas tube upon the striking of any other gas tube in the chain, a lesser plurality of input leads than gas tubes for receiving input signals applied to the circuit and a separate control device associated with each group of gas tubes, each control device having a first input, a second input, a third input and an output and operating to supply an electric signal to its output upon the supply of electric signals to its inputsjaccording to a predetermined order, each first input being connected to the resistance means of the gas tubes in the associated group, each output being connected to the particular signal carrying lead associated with the group wherein the gas tubes occupy succeeding positions in the chain relative to the gas tubes of the said associated group and the said second and third inputs being connected to the input leads so that the said second and third inputs of any control device are connected to ditferent ones of the input leads.

2. An electrical counting circuit according to claim 1 wherein the gas tubes are cold cathode gas discharge triodes.

3. An electrical counting circuit comprising a plurality of gas tubes connected in a chain and each having an anode, a cathode and a trigger electrode, the gas tubes forming a lesser plurality of groups than there are gas tubes and each group comprising at least two of the gas tubes that occur in the chain at a regular spacing which is the same for each group and which is such that adjacent gas tubes in the chain belong to difierent groups, individual resistance means connected in series with the anode to cathode gap of each gas tube to provide an electric signal when the associated gas tube is conducting, a separate signal carrying lead for each group of gas tubes, a separate coincidence device between each pair of consecutive gas tubes in the chain, each coincidence device having an input circuit connected across the resistance means of one gas tube of the associated pair, an output connected to the trigger electrode of the succeeding gas tube of that pair and an input connected to the particular signal carrying lead associated with the said succeeding gas tube and operating upon a coincidence of electric signals applied to its input circuit and its input from said resistance means and said particular signal carrying lead to apply an electric signal to its output and thereby to strike said succeeding gas tube, mutual extinguishing means which includes individual capacitance connected to each gas tube and resistance connected in common to all the gas tubes and which is to extinguish a conducting gas tube upon the striking of any other gas tube in the chain, two input leads for receiving input Signals applied to the circuit and a separate control device associated with each group of gas tubes, each control device having a first input, a second input, a third input and an output and operating to supply an electric signal to its output upon the supply of an electric signal to its said third input subsequent to the supply of coincident electric signals to its said first and second inputs, each first input being connected to the resistance means of the gas tubes in the associated group, each output being connected to the particular signal carrying lead associated with the group wherein the gas tubes occupy succeeding positions in the chain relative to the gas tubes of the said associated group, each second input being connected to one of the input leads and each third input being connected to the other one of the input leads.

4. An electrical counting circuit according to claim 3 wherein each control device comprises a pair of gas tubes each having an anode, a cathode and a trigger electrode, a first coincidence device having said first input, said second input and an output connected to the trigger electrode of the first gas tube of said pair and acting upon the coincidence of electric signals on said first and second inputs to apply an electric signal to its output and thereby to strike said first gas tube, individual resistance means connected to the cathode of each gas tube to provide an electric signal at the cathode when the associated gas tube is conducting and a second coincidence device having an input connected to the cathode of said first gas tube, said third input and an output connected to the trigger electrode of the second gas tube of said pair and acting upon the coincidence of electric signals from said cathode and said third input to apply an electric signal to its output and thereby to strike said second gas tube, the output of each control device being connected to the cathode of the associated second gas tube and there being provided mutual extinguishing means which includes individual capacitance connected to the cathode of each gas tube in the control devices and resistance connected in common to all those gas tubes and which is to extinguish a conducting gas tube in any control device upon the striking of any other gas tube in the control devices.

5. An electrical counting circuit according to claim 4 wherein the plurality of gas tubes and the gas tubes in said control devices are cold cathode gas discharge triodes.

6. An electrical counting circuit comprising a plurality of gas tubes connected in a chain and each having an anode, a cathode, and a trigger electrode, the gas tubes being individually allocated to two groups so that alternate gas tubes along the chain are in the same group, individual resistance means connected to the cathode of each gas tube to provide an electric signal at the cathode when the associated gas tube is conducting, a separate signal carrying lead for each group of gas tubes, a separate coincidence device between each pair of consecutive gas tubes in the chain, each coincidence device having an input connected to the cathode of one gas tube of the associated pair, an output connected to the trigger electrode of the succeeding gas tube of that pair, and an other input connected to the particular signal carrying lead associated with said succeeding gas tube and operating upon a coincidence of electric signals applied to its inputs from said cathode and said particular signal carrying lead to apply an electric signal to its output and thereby to strike said succeeding gas tube, mutual extinguishing means which includes individual capacitance connected to the cathode of each gas tube and resistance connected in common to the anodes of the gas tubes, and which is to extinguish a conducting gas tube upon the striking of any other gas tube in the chain, two input leads for receiving input signals applied to the circuit and two control devices each associated with a different one of the groups of gas tubes, each control device having a first input, a second input, a third input and an output and acting to supply an electric signal to its output upon the supply of an electric signal to its said third input subsequent to the supply of coincident electric signals to its said first and second inputs, each first input being connected to the cathodes of the gas tubes in the associated group, each output being connected to the signal carrying lead associated with the other group of gas tubes, each second input being connected to one of the input leads and each third input being connected to the other one of the input leads.

7. An electrical counting circuit according to claim 6 wherein each control device comprises a pair of gas tubes each having an anode, a cathode and a trigger electrode; a first coincidence device having said first input, said second input and an output connected to the trigger electrode of the first gas tube of said pair, and acting upon the coincidence of electric signals on said first and second inputs to apply an electric signal to its output and thereby to strike said first gas tube, individual resistance means connected to the cathode of each gas tube to provide an electric signal at the cathode when the associated gas tube is conducting and a second coincidence device having an input connected to the cathode of said first gas tube, said third input and an output connected to the trigger electrode of the second gas tube of said pair and acting upon the coincidence of electric signals from said cathode and said third input to apply an electric signal to its output and thereby to strike said second gas tube, the output of each control device being connected to the cathode of the associated second gas tube and there being provided mutual extinguishing means which includes individual capacitance connected to the cathode of each gas tube in the control devices and resistance connected in t Ommon to all thosegas tubes and which is to extinguish a conducting gas tube in any control device upon the striking of any other 'gas'tube in the control devices.

- 8. An electrical counting circuit according to claim 7 wherein the plurality of gas tubes and the gas tubes in said control devices are cold cathode gas discharge triodes. ,9. An electrical counting circuit according to claim 6 wherein two terminals are provided for connection to a source of electric current signals to operate the circuit and wherein a signal input circuit is connected on one side to said terminals and on the other side to said input leads, the signal input circuit comprising a source of predetermined potential and an electro-magnetic relay having a winding connected in a series circuit between said terminals to operate the relay in response to current signals supplied to those terminals, and there being contacts of the relay which are connected to the input leads and to said potential source and which, in their normal condition, connect said potential source to a particular one of the input leads and, in their operated condition, connect said potential source to the other one of the input leads. V

. 10. An electrical counting circuit comprising odd and Zeven gas tubes connected alternately, in a chain, each gas tube having an anode, a cathode and a trigger electrode, individual resistance means connected in series the anode to cathode gap of each gas tube to providean electric signal when the associated gas tube is conducting, two signal carrying leads respectively associated with the said odd and even gas tubes, a sep arate coincidence device between each pair of consecutive gas tubes in the'chain, each coincidence device having an input connected to the resistance means of the first gas tube of the associated pair, an output connected to the trigger electrode of the second gas tube of that pair andanother input connected to the particular signal carrying lead associated With said second gas tube and operating upon the coincidence of electric signals ap plied to its inputs from said resistance means and said particular signal carrying lead toapply an electric signal to its output'and thereby to strike said second gas tube,

12 mutual extinguishing means which includes individual capacitance connected toeach gas tube and resistance connected in common to the gas tubes and which is for extinguishing a conducting gas tube upon thestriking of any other gastube in the chain, two input leads for alternately receiving input signals applied'to the circuit and two control devices, each control device including an input circuit and an output circuit that is connected to the input circuit and having a first input and a second input connected to, said, input circuit and a. third input and an output connected to said output circuit, each input circuit operating upon the coincidence of electric signals on its said first and second inputs and when operated supplying an electric signal to the connection to its associated output circuit and each output circuit operating upon the coincidence of an electric signal on the connection from the associated input circuit with an electric signal on'its third inputand when operated supplying an electric signal to its output, one of said control devices having its first input connected to the individual resistance means of said odd gas tubes and its output connected to the signal carrying lead associated with said even gas tubes, the other control device having its first input connected to the individual resistance means of said even gas tubes and its output connected to the signal carrying lead associated with said odd gas tubes,

each second input being connected to one of the input leads and each third input being connected to the other one of the input leads.

7 References Cited in the file of this patent UNITED STATES PATENTS Ruhlig Apr. 23, 1957 

